Densities of Molten and Solid Alloys of (Fe, Cu, Ni, Co)-S at Elevated Temperatures - Literature Review and Analysis

Densities of solid and liquid Fe, Cu, Ni and Co, and their alloys both at the presence and absence of sulfur have been reviewed. Volumetric thermal expansions were used to estimate the densities at different temperatures. Densities of the alloys generally decrease with increasing temperature. For the pure metals the reduction in density as temperature rises from 25 oC to their respective melting point can be estimated to be about 7.05 ± 0.4 % just before melting and about 11.63 ± 0.92 on complete melting. According to the literature data and the analyzed results, at ambient pressure condition, density of the stoichiometric FeS changes from 4.615 g/cm3 at 25 oC to 3.8 g/cm3 at 1200 oC (17.7 %), density of the stoichiometric Cu2S changes from 5.65 g/cm3 at 25 oC to 5.18 g/cm3 at 1200 oC (8.3 %), density of the stoichiometric NiS changes from 5.5 g/cm3 at 25 oC to 5.025 g/cm3 at 1027 oC (8.5 ± 1.8 %) and density of the stoichiometric CoS changes from 5.45 g/cm3 at 25 oC to 4.88 g/cm3 at 1100 oC (10.45 %). A study on the Fe-S melts at 4GPa suggests that in sulfur-poor compositions, where solubility of sulfur is less likely to be affected by pressure, the density of the sulfides at isothermal conditions decreases in a similar fashion as under 1 bar, i.e., density decreases non-linearly with increasing composition of sulfur.Peer reviewe

Phase equilibria and thermochemistry of selected sulfide systems in the pyrometallurgy of Ni and Cu

A review of phase equilibria and thermodynamic data of Ni-(As, Se)-S and Cu-(As, Bi, Pb, Sb,Se, Te, Nb, Zn, Mo)-S systems was done. Particular emphases were given to the compilationand refine of the standard Gibbs energies of formations of equilibrium phases, which are ofinterest in the pyrometallurgical processes of copper and nickel production. Phase stabilities,phase relations and solubility limits of some equilibrium phases in the Ni-(As, Se)-S and Cu-Mo-Bi-Nb-S systems were also compiled and reviewed, based on the available literature.This work also reviews, updates, and extends the earlier reports. The Gibbs energies offormations and reactions are mostly presented as linear equations, in each temperature rangesof phase stabilities. List of thermal stabilities of some pure sulfides and sulfosalts were alsoreviewed and compiled (Appendix)

A thermodynamic assessment of the BaO-MgO, BaO-CaO, BaO-Al2O3 and BaO-SiO2 systems

Literature data concerning thermodynamic data for BaO including melting point, heat capacity, enthalpy increment, enthalpy of formation and entropy of formation were reviewed. The phase diagram data of the BaO-MgO, BaO-CaO, BaO-Al2O3 and BaO-SiO2 systems were evaluated and taken into account in the thermodynamic assessment in the present work. Associate model was employed to describe the liquid phase in the BaO-Al2O3 and BaO-SiO2 systems. Four sets of consistent thermo­dynamic parameters, which can explain most of the experimental data of the BaO-MgO, BaO-CaO, BaO-Al2O3 and BaO-SiO2 systems, were achieved. The calculated phase diagrams of BaO-MgO, BaO-CaO, BaO-Al2O3 and BaO-SiO2 systems were provided. By employing the optimized thermodynamic parameters, mixing of enthalpies of the liquid phase for the four systems and heat capacities for BaAl2O4 and BaAl12O19 were calculated and compared with the literature values

Sulfide Mineralogy - Literature Review

The aim of this study was to have an insight into the sulfide mineralogy, mainly based on sulfides mineralogical studies prior to the year 1975. In the first two chapters, the metal sulfides crystal structures and chemistries are reviewed. Then, the electronic interactions and chemical bonding followed by experimental methods in sulfides research with the proposed phase equilibria are reviewed. Phase relations in the (Cu, Ni, Zn)-S systems are discussed. Due to its influential and common appearance, in most natural sulfides (the common rock-forming minerals: po and py), the Fe-S system has been summarized relatively in detail. Sulfide petrology has been also discussed. The metal sulfides are the raw materials for most of the world supplies of non-ferrous metals. Their complex chemistry, as a result of high impurities association (such as As, Sb, Bi, etc...) and less base-metals content (metal poor rocks: composition of base-metal is less than 1 at.%), and the ever growing demand for the metals as well as the embroiling need to optimize minerals processing and sulfides smelting claim intense mineralogical studies. The main goal of such studies are to acquire accurate thermodynamic data which are useful to predict reactions and stable relationships, and in defining the limiting conditions under which phases may exist.Peer reviewe

Structural optimization of an elevator guide rail

Tässä diplomityössä tutustutaan hissin johteen rakenteeseen ja sen optimointiin. Työn tavoitteena on rakentaa laskentamalli, jota käyttämällä voidaan optimoida rakenteen massaa. Analyysit tehdään ANSYS-elementtimenetelmäohjelmistolla ja optimointi suoritetaan käyttäen SimPro-laskentatyökalua, jonka soveltuvuutta rakenteiden optimointiin selvitetään tämän tutkimuksen myötä. Tutkimuksessa optimoitavat parametrit ovat rakenteeseen liittyviä pituusmittoja ja johteen poikkileikkaus. Rajoittavana tekijänä optimoinneissa toimii johteen taipumasta aiheutuva kulma. Lisäksi on kokeiltu optimoida yhtä aikaa sekä rakenteen massaa että johteen taipumasta syntyvää kulmaa monitavoiteoptimointia käyttäen. Tutkimuksen tuloksina on saatu optimaaliset parametriyhdistelmät suunnittelumuuttujille tapauksiin, joissa suunnittelumuuttujien arvot ovat eri tavoin rajoitettuja. Näiden tulosten pohjalta on tutkittu, kuinka herkkä optimiratkaisu on kunkin suunnittelumuuttujan arvon muutokselle. Optimointiin käytetty SimPro-laskentatyökalu osoittautui helppokäyttöiseksi ja rakenteiden optimointiin soveltuvaksi työkaluksi, jonka avulla saadaan paljon tietoa tutkittavasta ongelmasta

On the dynamics of web transfer in an open draw

A paper web running in an open draw of a high speed paper machine is subjected to various internal and external forces which stretch it and which can ultimately rupture it. The forces arise from speed differences between various web transfer elements, from pressure loads transmitted through the surrounding air and from the effects of gravity, friction and drag. Since the web travels in a curved path, it is also subjected to centripetal forces, which can reach very high magnitudes.This study is concerned with the dynamics of paper web in an open draw. The constructed model takes into account external and internal forces acting on the web. There is provision in the model for determining variations in web tension caused by occasional external disturbances.The sensitivity of web tension to small external disturbances is shown in simulations. The length of the open draw is an important variable in web transfer dynamics. Another essential parameters which must be included are the aerodynamic drag forces, as they contribute to damping the resonance events during web transfer, and therefore to web stability

The Fast Silver Ion Conducting Solid-State Electrolytes for Deriving Thermodynamic Data

The electromotive force (EMF) method was described and some characteristic examples from the past and recent literatures were reviewed. The important experimental procedures for a successful measurement of an EMF of different galvanic cells at a certain temperature and determination of the thermodynamic properties of chemical compounds from the obtained EMF values were described. A typical galvanic cell arrangement in a furnace was presented. The two most common types of AgI-based solid electrolytes, AgI and RbAg4I5, were discussed in detail. The ionic conduction mechanisms and the application of the solid electrolytes in the EMF cells were described. In this work, we have also conducted EMF measurements using the fast Ag+ ion conducting solid-state electrolyte. The solid-state electrolyte Ag3GeS3I glass and the cathode material Ag4HgSe2I2 were synthesized and electrochemical cell (−)graphite|Ag|Ag3GeS3I glass|Ag4HgSe2I2|graphite(+) was assembled to measure the activity of Ag in the quaternary phase. The extremely low values of activity of silver in Ag4HgSe2I2 in the temperature range 412–482 K indicate that Ag4HgSe2I2 has superionic property. The obtained results and the determined thermodynamic values are presented and discussed